Field of the Invention
The present invention relates to an apparatus for manufacturing an optical fiber.
Description of Related Art
FIG. 15 is a schematic view showing a schematic configuration of an example of an apparatus of manufacturing an optical fiber of the related art.
The manufacturing apparatus includes a drawing unit 10 which forms a bare optical fiber 3 from an optical fiber preform 2, a cooling unit 120 which cools the bare optical fiber 3, a coating unit 30 which disposes a coating layer on the bare optical fiber 3 and forms an optical fiber intermediary body 4, and a curing unit 40 which cures the coating layer of the optical fiber intermediary body 4 to be an optical fiber 5.
During manufacturing the bare optical fiber, the bare optical fiber 3 is obtained by drawing the optical fiber preform 2 at the drawing portion 10. After cooling the bare optical fiber 3 at the cooling portion 120, a coating layer made of a resin is provided at an outer surface of the bare optical fiber 3 at the coating portion 30. The bare optical fiber 3 in which the coating layer is cured at the curing unit 40 is wound by winding means 70 through a pulley 50 and a take-up unit 60.
The bare optical fiber 3 obtained by drawing the optical fiber preform 2 is drawn toward a vertically lower direction along a linear path.
In the manufacturing method, there is a restriction on the height of the entire system as a factor affecting productivity. The reason that the height of the system is a main factor which restricts productivity is because it is necessary to ensure a distance for sufficiently cooling a bare optical fiber which is obtained by drawing the optical fiber preform.
When a new facility including a building is built, the restriction can be relaxed; however, an enormous cost is required for building a new facility, and when it is required that productivity is further improved in the future, it is necessary that a new facility will be built at higher cost.
As a method of relaxing the restriction, a method is included in which a direction changer including a non-contact retaining mechanism is used.
The non-contact retaining mechanism is for holding a target to be in a noncontact state using the pressure of a fluid such as air, and in the direction changer including the fluid bearing, it is possible to perform direction change with respect to the bare optical fiber without being in contact with the bare optical fiber (a bare fiber).
By using the direction changer, it is possible to change the direction of the bare optical fiber which is subjected to the fiber drawing from the optical fiber preform along the first path to conform to a second path (for example, refer to Japanese Patent No. 5571958 and Japanese Unexamined Patent Application, First Publication No. S62-003037).
In Japanese Patent No. 5571958, a manufacturing method is disclosed in which an apparatus for direction change including a groove into which an optical fiber is introduced and an opening formed in the groove is used. In this method, gas introduced to the apparatus is blown out from the opening through one inflow port, and the direction of the optical fiber is changed in a state where the optical fiber is floated due to the pressure of the gas.
A direction changer disclosed in Japanese Unexamined Patent Application, First Publication No. S62-003037 includes a guide groove which guides a bare optical fiber, and a blowout port for gas which is formed on a lower surface and both side surfaces of the guide groove (refer to Examples, and FIGS. 3A to 4). In the manufacturing method using the direction changer, the direction of the optical fiber is changed in a state where the optical fiber is floated due to the pressure of the gas blown out from four blowout ports.
However, in the manufacturing method described in the above-described Japanese Unexamined Patent Application, it is not easy to stably float the bare optical fiber in a tool for the direction changer.
The present invention has been made in consideration of the above-described circumstances and to provide a method of manufacturing an optical fiber and an apparatus of manufacturing an optical fiber capable of stably floating the bare optical fiber.